Friction clutch plate



P 1948- 8 D. E. GAMBLE 2,448,880

FRICTION CLUTCH PLATE Original Filed June 12, 1957 Int/mim- DavrlczfGarnfile Patented 7, 1948 FRICTION CLUTCH PLATE David E. Gamble, Tucson,Ariz., assignor to Borg- Chicago, III., a corpora- Warner Corporation,

tion of Illinois Original application Ju 147,936. Divided and he 12,1937, Serial No this application April 21;

1948, Serial No. 22,342

7 Claims. (Cl. 192107) My invention relates to improvements in frictionclutch plates, and more particularly to clutch plates of the so-calledcushion type comprising the driven assembly of a friction clutch.

' This application is a division of my copending application Serial No.147,936, filed June 12, 1937, for Friction clutch plate.

It has become a practice in the art of friction clutches to constructthe driven assembly, or friction clutch plate, in such manner as tosupport the friction facings thereof yieldingly upon the relativelyrigid hub-disc assembly of the plate, thus to permit the friction facingsupports to yield during compression of the plate in such manner thatthe friction facings, without undergoing change in shape, may adjustthemselves to the friction engaging surfaces of the clutch driveassembly. In my earlier U. S. Letters Patent Nos. 1,652,005-6-7, I havedisclosed clutch plates of the above-described type in which the outerregions of the clutch discs are fashioned to provide a. plurality ofrelatively yielding cushions upon which the friction facings aresupported. During compression of the plate such facings were capable ofmoving bodily, without distortion, relatively toward one another.

Later, clutch plates were constructed and adapted to commercial use inwhich independent relatively light steel spring cushions were mountedupon the outer side wall of the clutch disc, and in turn supported atleast one of the friction facings. Such plates possessed the advantageof providing any desired resistance to facing movement duringcompression of the plate by the simple expedient of choosing, at thetime of manufacture, cushions of proper resiliency, both disc andcushions being formed frombut two dies.

Such clutch plates as I have described. however, because the relativelyheavy metal of the clutch disc extended to the outer periphery of thefinished plate, possess what I choose to call relatively high spinninginertia. Stated in other words, the relatively high rotating mass of theperipheral portion of the plate brought about a delay in the shifting'oftransmission gears, as from one speed through neutral toanother speed.because the spinning inertia of the plate with the clutch disengagedcaused the plate with the relatively moving parts of the transmission todecelerate slowly and to delay synchronism of the engageabletransmission gears. This objection was particularly noticeable beforethe introduc.

tion of synchromesh transmissions.

It is an object of my present invention, thereinventio fore, to providean improved clutch plate having all the advantages of the independentsteel spring cushion plate as to preselection of cushion resistance, andin addition thereto, to provide a plate which possesses a relatively low"spinning inertia so that the thus to facilitate the quickening oftransmission gear shift.

Another object of my invention is to provide an improved friction clutchplate in which the friction facings and their cushion supportinginstrumentality is such as to provide for bodily movement of the twofriction facings, one relatively to the other, and both relative to thedisc.

These features are ones which assure complete surface to surfaceengagement between the facings and their friction engaging surfaces ofthe driving assembly, as well as the correction of slight misalignmentbetween the plane of the body of the disc and the plane of rotation ofthe driving assembly; 4

Another object is to provide an improved friction clutch plate whichissimple in construction, and which may be manufactured at a relativelylow cost. f

Another object of the invention is to provide an improved frictionclutch plate in which the spinning inertia is greatly reduced ascompared to prior plates, without sacrificing torsional load carryingcapacity. To this end, the invention contemplates a friction clutchplate including a hub. 'a mounting disc mounted on said hub, comprisinga substantially circular central disc portion of sheet metal of suchthickness as to be substantially unyielding and to adequately withstandthe torque loads imposed upon it during clutch operation, and aperipheral region having a low rotational inertia, said peripheralregion comprising a plurality of yieldable cushion members of materiallylesser thickness and weight per unit area than said disc portion, spacedfrom the periphery of said disc portion, neck members, of reducedcircumferential width compared to that of said cushion members, joiningsaid cushion members to the disc portion, and friction facings embracingand secured to said cushion members.

Other objects, advantages and uses of th invention will be apparentafter reading the following specification and claims, and afterconsideration of the drawings forming a part of the speciflcation, inwhich:

Fig. 1 is a fragmentary face elevation of a clutch plate constructed inaccordance with my plate may decelerate quickly,-

auaaao Fig. 2 is a cross sectional view substantially along the line 2-2of Fig. l;'

Fig. 3 is a sectional view along the line 3'--3 of Fig. 1; and

Fig. 4 is a view similar to Fig. 3 of a modified form of the cushion.

With reference to Figs. 1 to 3, inclusive, I have illustrated therein afriction clutch plate of the type intended for use in the frictionclutch, or so-called "engin clutch of a motor vehicle.

The clutch plate illustrated may comprise a hub 2, having splines 3 forengagement with the complementarily splined portion of a transmissionshaft (not shown), a circular mounting plate 4 of sheet steel secured,as by rivets 5, to the hub 2 and of an outside diameter notably lessthan the overall diameter of the complete clutch plate and annularfriction facings, of which there are two in number and indicated at 6and 1 respectively, preferably of an internal diameter greater th in theouter diameter of the disc 4. The faciogs 6 and I, it will be noted, arelocated concentrically of the disc 4 in parallel relationship to oneanother and to the plane of the body of the disc 4.

Each of the facings 6 and l are drivingly connected with the hub anddisc assembly 2-4 through the medium of a plurality of sets of resillentcushions 8 and 8, respectively, arranged in pairs in annular array aboutthe axis of the hub 2, each pair of cushions in close end to endrelationship with the next adjacent pair (see Fig. 1). The resilientcushions 8 constitute one set or row of cushions and the resilientcushions a constitute another set or row, with the cushions of one rowbeing axially offset and cooperating with the cushions of the other rowto provide for relative axial movement of the friction facings underclutch packing pressure.

Each of the cushions 6 and 8 is of general T-shaped configuration and isformed with an integral tab or foot 9 at its radially inward edge, thetab 9 being connected to the horizontally extending head or cushionportion by a narrow neck portion 21 of substantially lesscircumferential width than either the cushion portion or the tab 9. Thetabs 9 of each pair of cushions 8 and 8 are secured firmly by rivets illto the peripheral portion of the disc 4, both tabs 9 being locatedpreferably on one side of the disc and the rivets l extend throughsuitable openings ill and I0 in the tabs and disc, respectively. Thecenters of the openings i0" and Ill lie upon radii disposed on eitherside of the neck portion 21. with reference to Fig. 3, each of thecushions are formed'with their central portions flat, as indicated at Il, and with their circumferentially extending end portions, or wings,bowed, as indicated at l2, in such manner that the concave sides of thebowed wing portions face each other and the facings 6 and 1 may restdirectly upon the convex sides or crowns of the bowed cushion portions,the intermediate and flat portions ll of the cushions being in contactwith one another and in spaced relationship to the adjacent surfaces ofeach of the friction facings (see Fig. 3). The facing 6 may be securedto each of one of the cushions 8 by rivets i3 which extend through thefacing 6 and through one of the bowed portions l2, and the facing I maybe secured to each one of the cushions 8 by similar rivets I4 extendingthrough the facing I and through that one of the bowed portions I! whichis diagonally out of register with the adjacent rivet l3, as viewed inFig. 3. The attachment iii the cushions 6 and I to their associatedfacings 6 and I, in this manner, maintains the facings in substantiallyparallel relation, free from axial distortion.

A clutch plate constructed as herein described presents yieldingresistance to bodily movement of the facings relatively toward oneanother, such resistance being provided by the bowed portions of thepairs of cushions 8 and 8". Should slight misalignment demand bodily andcollective movement of the facings relatively to the disc 4, suchmovement or accommodation may take place, although in a properlyconstructed clutch plate and clutch driving assembly, such error inalignment does not frequently occur. During clutch engagement, thecushions may spread out circumferentially. This advantage, which is theresult of the arrangement of the rivets l3 and i4 relative to thecushions, prevents any internal stresses within the cushion memberswhich might otherwise impair efficient cushion operation, and which intime might result in mutilation of the cushions.

My improved clutch plate possesses relatively high torque transmittingcharacteristics, since each of the cushion members is secured firmly toone of the facings, and each cushion member is firmly fixed by aplurality of rivets In to the disc 4. There is no tendency of thecushions to yield circumferentially, since the torque transmittedbetween facing and hub assembly is transmitted edgewise substantiallythrough the plane of the bodies of the cushions, and this isparticularly so during complete engagement of the clutch when thecushions are compressed to their reasonable operative limit.

The major advantage attained by the clutch plate herein described is thepresentation of low spinning inertia, since the mass of the relativelythin steel cushions 8 and 8 is considerably less than would be the massof the disc 4 were it extended to the outer periphery of the plate, orwere the cushion members substituted for structurally distortedportions, of the disc 4 as has been the practice in times past prior tothe use of independent spring steel cushions in a manner I havepreviously described.

The reduction in spinning inertia in my improved clutch plate is onethat is very noticeable by the increase in rate of deceleration of theclutch plate and transmission drive shaft assembly. This reduction is ofsuch order that shifting of the gears from one speed through neutral toanother may take place in noticeably less time without clashing than ispossible in clutch plates of typical present construction.

At the same time, the construction and arrangement of the parts is suchthat the plate has ample torsional load carrying strength. Consideringthe disc 4 and the cushions 8, 6 etc,

collectively as a mounting plate, the peripheral region of whichcomprises relatively light thin cushions, it may be pointed out that thetorsional load becomes concentrated toward the center of the plate, andthe central disc portion thereof is accordinglymade relatively heavy andunyielding so as to withstand such concentrated torque loads. Thecushions are each secured to the central disc portion atcircumferentially spaced pointsso as to resist any tendency to pivotwhen subjected to the transmission of torsional load from the facings ofthe disc, and each cushion is, in addition, secured to a facing atpreferably a plurality of points, so as to further resist such pivotingtendencies.

Furthermore, the central disc portion apbend said neck regions under thetorque load. As

a result, the forces acting on the neck regions are largely shearingforces, which are adequately resisted by the neck regions. It will beunderstood that the reduced neck regions allow the circumferentiallyextended cushioning portions to freely flex during clutch engagement,without beinghindered by the attachment to the unyielding disc portionof the plate.

In Fig. 4 I have illustrated a modification of the construction of thecushions illustrated in Fig. 1. In this figure thecushions 8 and 8 areconstructed identically as to profile to the cushions 8 and l, but thebowed portions of each operating pair of cushions are formed so that oneportion I2 is bowed to a lesser extent than is the opposite bowedportion l2, and the bowed portion I! of one of the cushions of each pairis in register with the bowed portion I! of the opposite cushion of eachpair. The rivets i3 and It serve to connect the facings 6 and 1respectively, to the bowed cushion portions l2 and ll. without axialdistortion of said facings. This arrangement provides ailefinitetwo-stage cushion action during initial compression of the clutch plate.As the plate is first compressed, the facings i and I, which are engagedwith the portions 62 only of each of the cushions, are resisted in theirmovement relatively toward one another and to the plane of the body ofthe disc 4 by one-half of each of the cushion members, but upon furthercompression, each of the facings may engage with the portions l2 of thecushions, thus to substantially double the resistance offered by thecushions. This change in resistance takes place at a definite stage inrelative facing movement and provides a comparaticely light cushionresistance for initial, or slip clutch engagement," and the desiredincrease in cushion resistance during the stage just prior to and atfull clutch engagement.

In the clutch plate assembly shown in Figs. 1 to 3, and in Fig. 4,respectively, the series of .cushions connected with the respectivefriction facings are engaged during the application of clutch packingpressure, so that the flexible end portions of the T-shaped cushionsbend along lines generally coinciding with the sides of the flat regionsii to permit relative axial movement of the friction facings toward eachother.

While certain embodiments of the invention have been illustrated anddescribed herein, by way of operative examples, it will be understoodthat the principles of the invention can be embodied in clutch plateassemblies substantially differing in details of construction andarrangement from those disclosed herein, without departing from thespirit of the invention or the scope of the annexed claims.

I claim:

1. A friction clutch comprising a pair of axially spaced frictionfacings, and a plurality of spring metal-cushions, each of said springmetal cushions including a central region and a wing portion extendingcireumferentially on each side of said central region, said wingportions being bowed in a generally circumferential direction,

said cushions being arranged in registering pairs and disposed withtheir central regions in opposition and the concave sides of their wingportions facing in opposite directions, certain of said cushions beingin engagement with and attached to only one of said friction; facingsand other cushions being in engagement with and attached to only theother of said friction facings, saidcertain cushions and said othercushions being yieldably engageable with each other to resist axialmovement of the friction facings in relation to each other under clutchpacking pressure.

2. A friction clutch comprising a pair of ax-.

ially spaced friction facings, and a plurality of spring metal cushions,each of said spring metal cushions including a central region and abowed wing portion extending circumferentially on each side of saidcentral region, said cushions being arranged in registering pairs anddisposed with their central regions in abutment and the concave sides oftheir wing portions facing each other, so that the convex sides of thewing portions of each cushion are in engagement with only one of saidfacings, and means attaching one wing of the diagonally opposite 'wingportions of each pair to the facing in engagement therewith, thecushions of each registering pair being yieldingly engageable with eachother to resist axial movement of the friction facings in relation toeach other under clutch packing pressure.

3. A friction clutch plate comprising a nonyielding substantiallycircular disc, hub means for mounting said disc upon a shaft, spacedapart friction facings in parallel relationship to one another and tothe plane of the body of the disc, said friction facings being locatedradially outwardly of the periphery of said disc, and a plurality ofyieldable cushions of high torque transmitting strength but ofmaterially lower weight per unit area than that of said disc, disposedbetween said facings in annular array about the axis of said disc, eachof said cushions having an inwardly extending portion firmly secured atits radially inward extremity to said disc, and each cushion beingsecured to at least one of said facings, each of said cushions includinga central region and a wing portion extending circumferentiaily on eachside of said central region, said wing portions being bowed in agenerally circumferential direction, said cushions being arranged inregistering pairs,- t e cushions of each pair being disposed with th ircentral regions in abutment and theconcave sides of their wing portionsfacing each other, one of the facing wing portions being bowed to agreater extent than the other, one of the cushions of each pair beingsecured to only one of said facings and the other cushion of each'pairbeing secured only to the other of said facings, the wing portions ofthe cushions of each pair being engageable with each other yieldably toresist movement of the facings toward one another in a plurality ofstages during the application of clutch packing pressure.

4. A clutch plate assembly, including: a central hub; an annularmounting member carried by said hub in concentric relation to the axisof said hub; a pair of axially spaced annular friction facings disposedradially outwardly of the periphery of said mounting member; means forsupporting one of said friction facings in torque transmitting relationto said mounting member and adapting said one friction facing for axialmovement relative to the other friction facing,

said supporting means including a plurality of independent resilientstructures extending in a generally radially outward direction from saidannular mounting member and between said friction facings, and attachedto said one'friction facing, each of said radially disposed resilientstructures being particularly characterized by a foot portion overlyingand secured to said annular mounting member, a cushion portion disposedbeyond the periphery of said mounting member and being adapted to flexunder clutch packing pressure, and an intermediate portion ofsubstantially less circumferential width than either said foot portionor said cushion portion; and other supporting means engageable with thecushion portions of said first-mentioned supporting means under clutchpacking pressure, said other supporting means being attached to saidother friction facing and to said annular mounting member, said twosupporting means being so arranged in relation to said friction facings,respectively, as to maintain said friction facings in substantiallyparallel relation to each other so as to enable both said frictionfacings to function uniformly throughout their operating surfaces underclutch packing pressure.

5. A friction clutch plate comprising a central mounting means; a pairof axially spaced annular friction facings disposed radially outwardfrom the periphery of said mounting means; means for connecting one ofsaid friction facings in torque transmitting relation to said mountingmeans and including a series of circumferentially spaced, individualsheet metal friction-facing supports carried by said mounting means andextending in a generally radial direction and attached to one frictionfacing only, said supports being of a generally T-shape and having acircumferentially extending head portion disposed between said frictionfacings, said head portion having flexible end regions; and otherfriction-facing supporting means carried by said mounting means andconnected only to said other friction facing and engageable with saidflexible end regions of said first-mentioned supports to effect flexingof said end regions yieldingly to resist axial movement of at least onefriction faoing toward the other friction facing under clutch packingpressure, said series of supports and said other supporting means,respectively, being so constructed and arranged relative to theirassociated friction facing as to maintain said associated frictionfacing free from axial distortion.

6. A friction clutch plate comprising a central mounting assembly; apair of axially spaced annular friction facings disposed radiallyoutward from the periphery of said mounting assembly; means forconnecting one of said friction facings in torque transmitting relationto said mounting assembly and including a plurality of circumferentiallyspaced, independent, sheet metal supporting structures each connected tosaid mounting assembly and extending in a generally radially outwarddirection therefrom with portions lying between said friction facings,each said supporting structure being of a generally T-shape and having aflat radially extending region between said facings withcircumferentially extending flexible portions at the sides of said flatregion and in a plane offset from the plane of said flat region; meansattaching each of said supporting structures to said one frictionfacing; and other supporting means carried by said mounting assembly andconnected to said other friction facing and disposed in a plane otherthan the plane of said flexible portions for engagement therewith toeffect flexing of said flexible portions yieldingly to resist axialmovement of one of said friction facings towards the other frictionfacing under clutch packing pressure.

7. A friction clutch plate as defined in claim 6, in which the flexibleportions bend along lines generally coinciding with the sides of theflat region.

DAVID E. GAMBLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,541,883 Wemp June 16, 19251,945,382 Saks Jan. 30, 1934 1,992,626 Nutt Feb. 26, 1935 2,027,650 NuttJan. 14, 1936 2,037,928 Saks Apr. 21, 1936 2,324,913 Daukus July 20,1943 FOREIGN PATENTS Number Country Date 388,704 Great Britain 1933794,147 France 1936

